Apparatus for indicating the amount of pressure in pneumatic tires for automobiles



APrll 1939. F. a. LEAVENWORTH -r AL ,155, APPARATUS FOR INDICATING THE AMOUNT OF PRESSURE IN YNEUMATIC TIRES FOR AUTOMOBILES Filed Oqt. 22, 1934 3 Sheets-Sheet 1 J 6 v 43 LEFT FRONT RIGHT mom- I I 14 'Xfi'? J8 '54 10 L manr LEFT REAR REAR 48 I J a5 5148? 15 I (25 1 l I :z i-b 3 14 l/ A RO mam" FRONT AxL'g 18 5g a1 74 75 LEFT REAR 78 v 1 16a .AREAR A "7 Apnl25, 1939- F. a. LEAVENWORTH Er AL- 2,155,355

1 APPARATUS FOR INDICATING THE AMOUNT OF PRESSURE I PNEUMATIC TIRES FOR AUTOMOBILES Filed Oct. 22, 1954 5 Sheets-Sheet 2 FRONT 1 v RIGHTFRONT LEFT J: V 14 rlo Rlmrr v REAR I LEFT REAR zwm P 'F. s. LEAVENWORTH ET AL 2,155,865

APPARATUS FOR INDICATING THE AMOUNT OF PRESSURE IN PNEUMATIC TIRES FOR AUTOMOBILES Filed Oct. 22, 1934 3 Sheets-Sheet 3 Patented Apr. 25, 1939 APPARATUS FOR INDICATING AMOUNT 0F PRESSURE IN PNEUMATIC TIRES FOB AUTOMOBILES ma 6. Leavenworth, Oak Park, and man J. Green, Chicago. 111., aseignors to William Hartman trustee I October 22, 1984, Satin! No. 749,3 7'

19 Claims.

The invention relates to apparatus for indicating the amount of pressure in pneumatic tires, and one object thereof is to provide an apparatus of thischaracter which is adapted to be installed on an automobile and includes an indicator on the dashboard having means for indicating the ,amount of pressure of the front and rear tires of the automobile.

Another object of the invention is to provide an apparatus of the type under consideration in which the indicator on the dashboard of the automobile is controlled for pressure indicating purposes by means of a pair of devices which are mounted one on the central portion of the front axle of the automobile and the other on the central portion of the rear axle, and operate in response to any inclination of the axles due to tire deflation. i

A further object of the invention is to provide a pressure indicating apparatus of the last mentioned character in which the indicator controlling devices on the axles are so arranged and connected with respect to the indicator that the indicating means of the latter will not give a false reading as far as the amount of tire pressure is concerned when the automobile is tilted sidewise as the result of being driven or parked on a laterally sloping roadway or other surface. I

A still further object of the invention is to provide an apparatus of the type and character under consideration which is generally of novel construction, may be manufactured and installed at a comparatively low cost and serves efllciently and accurately to indicate to the driver or occupants of the automobile to which the apparatus is applied the amount of pressure in each of the four tires of the automobile.

Other objects of the invention and the various advantages and characteristics of the present pressure indicating apparatus will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features whlchare hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawings which accompany and form a part of this specification or disclosure and in which like numerals of reference denote corresponding parts throughout the several viewsz' Figure l is a diagrammatic view showing a pressure indicating apparatus embodying the in-' vention in its assembled position with respect to an automobile and illustrating the position of the indicating means of the dashboard indicator when the tires of the automobile are properly or fully inflated and the axles of the automobile are heri- Figure 2 is a diagrammaticviewshowing the.

position of the indicating d when the axles of the automobile are tilted side wise in one direction as the result of the automobile being driven or parked on a laterally sloping roadway or surface} I Figure 3 is a diagrammatic view illustrating 6 the manner in which the indicating means of the indicator shows tire deflation when any of the four tires of the automobile have less than normal air pressure therein;

Figure 4 is a detail view of the indicating means or part of the indicator which serves to show the amount of pressure in the right front and right rear'tires of the automobile to which the apparatus is applied;

Figure 5 is a sectional view of one of the axle supported devices for controlling the indicator;

Figure 6 is a detail sectional view of the indicator; and

Figure "I is a diagrammatic view of an apparatus embodying a modified or alternative form of the invention.

The apparatus which constitutes the preferred form of the invention and is shown in Figures 1 to 6 inclusive of thedrawings, is adapted and designed for use in connection with an automobile A andserves to indicate the amount of air pressure in the tires of the automobile. The automobile A is shown diagrammatically in Figures 1. 2 and 3 and is supposedly of conventional or standard design and construction in that it includes a front axle II, a rear axle II, and a dashboard I2. The front axle is connected by springs (not shown) to thechassis of the automobile as well understood inthe art, and includes a right hand dirigible wheel Il with a pneumatic tire Ila, and a left hand dirigible wheel ll with apneumatic tire I la. The rear axle II is located the front axle and has a rightjhand traction wheel I! with a pneumatic tire Ito, and a left hand traction wheel-I0 with a'p'neumatie tire Ila. The dashboard if is supported on the chassis of the automobilein front of the usual seatfor the driver or operator of the automobile. The 'pressure'indicating apparatus of Figures 1 to is inclusive. is for the e ecmciu type and comprises an indicator I1 and "a pair of indicator controlling devices I. and ill. w

The indicator I'l comprisesa casingfl which is mounted in the dashboa'rd II within'the range of visionof the driver or'operat'or of'the automobile A and has face plate 2| across'the central portion thereof and a glass plate across its front so that the face plate is visible to the driver. in addition-to the casing 20 the indicator the right, front tire "a and the right rear tire Ila.

plate 2| and supports the pointer 23 so that it is free to swing back and forth relatively to the scale 25. As shown in Figure 4 the scale 25 has graduations or markings 21 on the left hand side to indicate the amount of pressure in the right front tire |3a of the automobile and has graduations or markings 23 on its right hand side to indicate the amount of pressure in the right rear tire |a. The pointer 23, when in a vertical position, points to the central portion of the scale 25 and indicates that both the right front and right rear tires are normally or properly inflated. When'the pointer swings to the left hand side of the scale it indicates a decrease in pressure in the front right tire, and when it swings to the right hand side of the scale 23 it indicates a decrease in pressure in the right rear tire l5a. The graduations or markings 21 and 23 are preferably in the form of percentages of tire inflation so that the driver of the'automobile may, by noting the position of the pointer 23 with respect to the scale 25, determine the percentage of pressure in either the right front or right rear tire as computed from normal or proper pressure. The shaft 23 is rocked for pointer swinging purposes by means of an arm 23 and a pair of fine wires 33 and 3|. The arm 23 is disposed in the rear portion of the casing 23 of the indicator and is fixed to and extends radially from the shaft 23 as shown in Figure 4. The wire 33 extends downwardly and outwardly in one direction and'has one end thereof connected to the distal end of the arm 23 and its other end connected to a tension spring 32. The wire 3| extends downwardly and outwardly in the opposite direction and is connected at its upper end to the distal end of the arm 23. The lower end'of the wire 3| is connected to the tension spring 33 and this spring together with the spring 32 operates through the medium of the wires 33 and 3| and the arm 23 to hold the pointer in its vertical position. The tension spring 32 is anchored to an adjusting screw 34 in a bracket 35 in one portion of the indicator casing 23. The lower end of the tension spring 33 is attached to an adjusting screw 33 in an angle bracket 31 in I another portion of the casing 23 of the indicator.

By adjusting the screws 34 and 33 the tension of the springs 32 and 33 may be regulated so that normally .the pointer is held in its vertical position. .The wires 33 and 3| are formed of Nichrome or like material and are adapted as hereinafter described to have current passed through them for pointer shifting purposes.

When current is passed through the wire 33 the wire due to its fineness becomes heated and lengthens. This in conjunction with the action of the tension springs Hand 33 causes the-pointer 23 t swing toward the left hand side of the scale 25. When current isv passed through the wire 3| the latter, as in the case of the wire 33, becomes heated and lengthens andcauses the pointer 23 to swing to the right hand side of the scale 25. 1

The pointer 24 is located adjacent to the pointer 23 in the casing 23. Itis disposed between the face plate 2| and the glass plate 22 of the casing and coacts with an arcuate scale 33 on the face plate 2| to indicate the amount of pressure in the left front and left rear tires I40 and Mia of the automobile A. A rock shaft 33 like the rock shaft 23 for the pointer 23, serves to support the pointer 24 so it is free to swing back and forth relatively to the scale 33. The left hand side of the scale has graduations or markings 43 for indicating the amount of pressure in the left front tire Ma and the right hand side of the scale 33 has graduations or markings 4| for indicating the amount of pressure in the left rear tire |3a. The pointer when in a vertical position points to the central portion of the scale 33, and indicates that both the left front and left rear tires are under normal or proper air pressure. Rocking of the shaft" for pointer swinging purposes is effected by means of an arm 42 and a pair of fine Nichrome wires 43 and 44. The arm 42 is fixed to and extends radially from the shaft 33 and is located in the rear portion of the indicator casing 23. The Nichrome wires 43 and 44 are connected to the distal end of the arm 42 and extend downwardly and outwardly in opposite directions. A tension spring 45 and a tension spring 43 are applied to the lower ends of the wires 43 and 44 respectively and operate normally to hold the pointer 24 in its vertical position. When current is supplied to either the wire 43 or the wire 44, as hereinafter described, the wire heats and as a result of the lengthening thereof causes a deflection of the pointer 24 with respect to the scale 43. The arms 23 and 42 are formed of insulating material. Current is supplied to the wires 33 and 3| for the pointer 23 and the wires 43 and 44 for the pointer 24 from a battery 41 which if desirable may be the regular storage battery of the automobile A. A conductor 43 leads from one side of the battery 41 to a pair of branch conductors 43 and 53. The branch conductor 43 is connected by a flexible wire 5| to the upper ends of the wires 33 and 3| and the conductor 53 is connected by a fieldble wire 52 to the upper ends of the Nichrome wires 43 and 44. The flexible wires 5| and 52 are provided for the purpose of permitting the pointers 23 and 24 to swing freely. The wires 33 and 3| are preferably covered with tubular strips 53 of asbestos, and the brackets and 31 are suitably insulated from the casing 23 of the indicator. The Nichrome wires 43 and 44 for the pointer 24 are also covered with tubular strips of asbestos or like material and the springs and 43 therefor are connected to adjusting screws (not shown) similarly to the tension springs 32 and 33 for the wires 33 and 3|. The supply of current tothe Nichrome wires 33, 3|, 43 and 44 is controlled by means of the controlling devices l3 and I3.

The controlling device I3 is associated with the front axle |3 of the automobile and comprises a tube 54 and a pair of resistance elements 55 and 53. The tube 54 is formed of glass or any other suitable material and is mounted in a housing 51 on the central portion of the axle II. This housing 5| is shaped so as to hold the tube 54 in parallel relation with respect to the axle l3 and has a removable cover 53 for holding the tube in place in it. The tube 54 is fllled approximately half-way with mercury 53 and has closed ends. A wire 33 leads downwardly from a contact 3| in the bottom of the tube and is grounded in any suitable manner. The resistance element 55 is located on top of the cover 53 and extends parallel with and over the end of the tube which faces in the direction of the right front wheel II of the automobile. A conductor 32 extends between the inner end of the resistance elements 55 and the bracket 35 for the adjusting screw 34, and a wire 33 extends between the outer end of the resistance element 55 and a contact 34 in. the extreme outer end of the mercury charged tube 54. When the axle of the automobile tilts downwardly in the direction of the wheel tablishe's the following electrical circuit, battery l'l, conductor", branch conductor 4!; flexible wire II, Nichrome wire 30, spring 32, adi'usting screw 34, bracket ll, conductor 02, re-

listance elementf ll wire 03, mercury 58, and" ground ill. When this circuit is established the Nichrome wire II due'to the flow of current therethroughe becomes heated as previously pointed outfand due to the increase in the length v thereof as theresult of its increase in temperature causes the pointer 23 to swing to the'left hand side of the scale and to indicate by way of the graduationsor markings 121' the deflated condition of the right front tire ofthe autmnov bile. By reasonof the fact that the resistance element BI is included in the circuit. there is but -a comparatively small amount of current DQ881- ing through the Nichrome wire with the result that the deflection or the pointer I is comparatively small. In 'order to increase the deflection of the pointer as the downward tilting or. inclination of the axle ll increases as the result of further or increased deflation of the tire Ila a group of wires 88 is provided. These wires. as shown in Figure 5 of the drawings, leads from diiierent portions of the resistance element W to contacts I. in the upper right hand end of the tube M. The-contaots M are arranged in longitudinal series and are adapted successively 'to'be immersed in the mercury during downward tilting of the axleas indicated in Figure 3. As a result of this arrangement the resistance element 5! is included in the aforementioned circuit in decreasing amounts as the inclination or tilt of the tube 5| increases. As the resistance element is progressively cut out the current through the Nichrome wire 30 increases with the resultthat this wire progressively increases in length and causes aprogressive deflection of the pointer 23 with respect to the graduations or markings 11. These graduations are preferably made so that the pointer will indicate a'0% of air in the tire "a. when the pointer is shifted to the extreme left hand side of the scale 23 and the tilting of the tube is such that the resistance element 55 is completely cut outof the circuit. As the result of the arrangement of the wires 85 the degree of tilting of the tube ll determines the degree of deflection of the pointer 23 with respect to the graduations or markings 21. When the right front tire Ila is fully inhated and the tube 54 is in a horizontal position the mercury is out of contact with the contacts M and 88, as shown in Figure 5, with the result that no current flo'ws through the Nichrome wire III and the pointer 23 remains in its normal vertical position Becausethe lengthening" of the Niehrome wire II is not instantaneous when current passes therethrough the pointer fl is not deflected when the wheel ll encounters a depression or hole in the roadway and the mercury I! momentarily is brought into engagement or contact with the contacts and.

- The resistance element I. is located over and 1 extends parallel with ehd'of the when which projects in the direction of the left front wheel I! of thej'automobile." The inner end .of

this resistan'ceelement is connected by aconductor '1 to the spring ll at the lower end of the Nichrome wire 48, and a wire a is connected to the outer end of the resistance element 6.

and leads to a contact in-the upper portion a wire IO.

of the extreme left hand end of the mercury charged tube 84. When the axle ll tilts downwardly in the direction-of the left front wheel I4 as the result of deflation of the tire Ila, the tube I4 tilts correspondingly and the following electrical circuit is established as the result of the mercury I. contacting with the contact '9:

battery 41, conductor ll, branch conductor 30, Nichrome wire 0, tension spring ll, conductor h I, resistance element II, wire OI. mercury 5|,

andground ll. When this cirouit is establishedthe Nichrome wire 4: becomes heated,

and as the result of the lengthening thereof causes a deflection of the pointer 24 toward the graduations or markings ll on the scale ll. In

and the resistance element ll whereby the resistance element is progressively cut out as the downward tilting of the tube in the direction of the left front wheel ll increases. The graduations or markings ll on the scale 38 are so arranged that the pointer "indicates a 0% of air pressure in the tire Ila when the latter is fully deflated and the mercury in'the tube 54 as the result of maximum tilting of the axle Il contacts with the innermost contact II. When the axle III is horizontal as the result of full or normal inflation of the tire Ila, the mercury 59 does not contact with the contacts 69 and II and as II, and has a ground wire 18 for the mercury.

Theresistance element I3 is located over and extends paraliel with the end of the tube "which faces in the directionof the right rear wheel I5. It is connected by a conductor" to the bracket 7 31 for the adjusting screw 36 and has wires 18 between diflerent portions thereof and contacts 18 in the upper portion of the right hand end of the tube II. The wires II and thecontacts I! are the same in arrangement as the wires between the resistance element I and the contacts N and 83. When the axlell tilts downwardly in the direction of the right rear wheel I! as I the result of deflation of the tire 'Il a the mercury "in the tube I! flows into contact with the contacts I! and establishes the following electrical circuit, battery 41, conductor ll, "branch conductor 40, Nichrome wire OI, tensionspring a, adjusting screw IO, bracket 31,, conductor 11. resistance element 18', mercury II; and ground current through the Nichrome wire ii the latterv becomes heated and as as the result w en this circuit isestablished so that T of lengtheningthereof deflects thepointer 23 toward the graduations or markings 2. on the scale 28 and thus discloses deflation of the right rear tire Iia to thedriver or operator of thej'automobiler 'lhe wires and contacts-.10.?" are so arranged that the resistance element 18 is progressively cut out of the circuit as the tilting of the axle II in the direction of the wheel I5 increases. Because of this the deflection of the pointer 23 toward the graduations or markings 28 increases as the deflation of the tire I5a increases. When the automobile A is driven over a roadway which slopes laterally in the direction of the right front and rear wheels I8 and i5 as indicated in Figure 2 of the drawings, there is no deflection of the pointer 28 in either direction due to the fact that although circuits are established through the wires 80 and 8i the wires heat and lengthen uniformly. This feature is of importance as far' as the apparatus is concerned inasmuch as there is no false reading of the indicator when the automobile is driven on a laterally inclined roadway. The resistance element 14 overlies and extends parallel with the end of the tube I2 which faces or extends in the direction of the right rear wheel i6. It is connected at its inner end to the tension spring 48 for the Nichrome wire 44 by a conductor 80 and has wires 8| which lead from different portions of it to a longitudinal series of contacts 82 along the upper portion of the left hand end of the tube I2. When the axle II tilts downwardly in the direction of the wheel I 6 as a result of deflation of the left rear tire iii: the tube I2 tilts correspondingly and the mercury I5 engages the contacts 82 to establish the following electrical circuit through the wire 44, battery 41, conductor 48, branch conductor 50, Nichrome wire 44, tension spring 48, conductor 80, resistance element I4, wires 8I,-mercury 15, and ground wire 16. Upon completion of this circuit the wire 3i as the result of cur-- rent passing therethrough becomes hot and lengthens and causes the pointer 24 to swing toward the graduations or markings 4i so as to indicate deflation of the left rear tire Ilia. Because of the arrangement of the contacts 82 the resistance element I4 is progressively cut out of the circuit as the tilting of the axle ii increases toward the wheel i6. Because. of this the flow of current through the Nichrome wire 44 is con trolled so that the wire effects increased deflection of the pointer 24 with respect to the graduations 4i as deflation of the tire iia increases. If the automobile A is driven over a roadway which slants in the direction of the left front and rear Wheels I4 and it there is no deflection of the pointer 24 with respect to the graduations or markings 40 and 4| inasmuch as current is caused to pass through both Nichrome wires 48.

The operation of the apparatus of Figures 1 to 6 inclusive is as follows: When all four tires of the automobile are fully inflated, as shown in Figure 1, the axles I0 and Ii are horizontally disposed and there is no contact between the mercury in the tubes 54 and I2 and the contacts for the resistance elements 55, 50, 18 and 14. Because of this no current flows through the Nichrome wires 30, 8|, 48 and 44 and the pointers 28 and 24 are held in a vertical position with respect to the scales 25 and 88 and indicate full inflation of the tire. In the event of puncture or deflation of any of the tires of the automobile such for example as the right front tire Ila the axle I0 tilts downwardly in the direction of the wheel I8 and causes the tube 54 to tilt so that the mercury 58 is brought into contact with the contacts 04 and 60. As soon as the mercury is brought into contact with the contacts, current flows through the Nichrome wire 80 and causes the latter to lengthen as the result of heat and to deflect the pointer 28 towards the markings 21 and thus to indicate the deflated condition of the tire in on the scale 25. When the left front tire is punctured so that the axle I8 is tilted in the opposite direction the pointer 24 because of the passing of current through the Nichrome wire 48 swings toward the left hand side of the scale 88 and registers the deflated condition of the tire on .the markings 40. In the event of deflation of the right rear tire Ila the pointer 28 swings to the right and indicates the condition of the tire on the graduations or markings 28 of the scale 28. Likewise when the left rear tire i8 is punctured or otherwise becames deflated the condition of the tire is recorded or indicated by swinging of the pointer 24 toward the right hand end of the scale 88.

The apparatus of Figures 1 to 6 inclusive is comparatively simple as far as construction is concerned, and may be manufactured at a low and reasonable cost. It is extremely efllcient in operation due to the fact that the controlling devices I 8 and I8 are so arranged and connected with respect to the indicator II that the pointers 28 and 24 will not give a false reading as far as amount of tire pressure is concerned when the automobile is tilted sidewise as the result of being driven or parked on a laterally sloping road, 3

or when the automobile is driven over a rough roadway and the axles are momentarily tilted as the result of the wheels encountering holes or other depressions.

The apparatus which is shown in Figure 7 of the drawings and which constitutes a modified or alternative form ofthe invention, comprises an indicator I00, and a pair of controlling devices IM and I02. The indicator like the indicator ll of the apparatus of Figures 1 to 6 inclusive of the drawings, is mounted in the dashboard of the automobile to which the apparatus is applied within the range of vision of the driver or operator of the automobile. It embodies a casing with a face plate I08 and includes a pointer I04 and a pointer ill. The pointer I04 is pivoted at one end thereof and coacts with an arcuate, graduated scale I00 on the face plate I08 to indicate the amount of pressure in the right front and right rear tires of the automobile. The scale has markings ill on its left hand side in the form of percentages of inflations of the right front tire and embodies markings ill on the right hand side thereof in the form of percentages of pressure or inflation of the right rear tire. The pointer I05 is pivoted at one end thereof similarly to the pointer I04 and coacts with an arcuate, graduated scale I08 on the face plate I08 to indicate the amount of pressure in the left front and rear tires of the automobile. The left hand side of the scale has markings III for the left front tire and the right hand side of the scale has markings III for the left rear tire. The controlling device III is secured on the central portion of the front axle of the vehicle and comprises a closed tube I I2 of glass or like material. This tube is suitably mounted on the axle and has a bailie in the central portion thereof. This baiiie extends downwardly to a point slightly above the bottom of the tube and forms a chamber II8 on one side thereof and a chamber II4 on its other side. The chamber H8 is positioned directly opposite the right front wheel of the vehicle and communicates with a hollow head III by way of a tube H0. Hie-head is ted in the casing of the indicator I and ma diaphragm H1 at one side thereof. This hragm is disposed opposite the pointer I04 and has a pad IIO which engages the central portion of the pointer and operates when the diaphragm is outwardly distended to swing the pointer toward the markings I01 on the left hand side of the scale I00. As shown in Figure '1 of the drawings the tube H2 is approximately onehalf way filled with mercury. The head II as well as the tube I I0 and the portion of the chamber III which is notfllled with mercury is filled with oil or a like liquid. When the'tube H2 is tilted downwardly as the result of deflation of the front right tireof the automobile, the mercury in the tube flows into the chamber H0 and forces the oil in the chamber upwardly through the tube III into the head I I0. As a result of inflow of oil in the head III the diaphragm H1 is outwardly distended so that the pointer I04 swings over toward the markings I01 and indicates the deflated condition of the right front tire of the automobile. The chamber Ill is located opposite the left front wheel of the automobile and communicates with a head Illa by way of a tube H0. The head is located adiacent the pointer I00 and has a diaphragm I20. The latter has a pad.,I2I which engages the central portion of the pointer I00 and serves to shift the pointer to the left hand side of the scale I00 when the diaphragm is distended. The headv la and also the tube H0 and the portion of the chamber I I! which is not fllled with mercury are filled with oil. When the tube I-I2 tilts toward the left front wheel of the automobile as the result of deflation of the left front tire the mercury in the tube surges over into the chamber Ill and forces the oil in the chamber through the tube II! into the head IIOa. The inflow of oil into the head causes the diaphragm I20 to expand with the result that the pointer I0! is swung in the direction of the markings H0 and indicatesthe degree of deflation of the left front tire of the automobile.

The controlling device I02 ismounted on the a central portion'of the rear axle of the automobile and consists of a tube I22. The latter is positioned in" parallel relation, with the axle and embodies a centrally downwardly extendingbaffle or cross-wall I23 which divides the tube into a pair of connected chambers! and I20. The chamber I24 is positioned opposite to the right rear wheel of the automobile and communicates with a head I20 by way of atube I21. The head has a diaphragm I20 with a pad I20. The latter contacts with the central portion of the pointer I04 and operates when the diaphragm is distended to shift the pointer toward the right hand side of the scale I00. The tube I22 is fllledapproximately half way with. mercury and the head I20 and also the tube I21 and the portion of the chamber I24 without mercury are filled with oil. when the tube I22 tilts to the right as the result of deflation of the right rear tire, the oil in the chamber I24, due to the surging of the mercury into the chamber flows upwardly through the tube I21 to-the tube I20. As soon as the oil flows into the head the diaphragm I20 is distended and'causes the pointer I04 to\ swing to the right hand side of the scale I00 and to indicate on the calibrations I08 the deflated condition oi the right rear tire. The chamber I20 communicates with a head I00 by way'of a tube Ill. The head is-lo'cated adjacent the pointer 75 Ill andincludes a diaphragm I02. This dia- 'in'g matic tires thereon,- of a tire indicator mounted .on the automobile and having means for indiphragm central portionof the pointer I20 and operates when the diaphragm is distended to swing the pointer I05 'to the right hand side of the scale I00. The head I30 and also the tube IOI and the upper portion of thechamber I20 are fllled with oil so that the diaphragm is distended when the tube I22 tilts to the left, as the result of defla tion of the left rear tire'of the automobile. The operation of the apparatus of Figure '7 is the has a pad m which bears against the I same as that-of Figures 1 to 6 inclusive except i When the automobile is tilted to the right as a result ofbeing on an inclined roadway the diaphragms H1 and I are simultaneously, distended with the result that the outward force or pressure of one neutralizes that of the other and causes no deflection of the pointer I04. When any one of the four tires of the automobile such for example as the rightfronttire is punctured, and as a, result causes the front axle to tilt downwardly in the direction ofthe right front wheel, the pointer I04 swings to the'left as the result of the pressure developed in the head H5 and indicates on the markings, I01 the degree of deflation of the tire.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scopeof the invention.

Having thus described claim as new and desire to secure by Letters Patent is: f

1. The combination with a vehicle having wheels with pneumatic tires thereon, of a tire indicator mounted on the vehicle and havin means for indicating the variousdegrees of deflation of the tires, and means for actuating said indicating means comprising a source of electric current, a plurality of circuits supplied with curthe invention, what we rent from said source, and means controlled'bv tilting due to tire deflation for varying the flow 'mobile and having means for indicating the var-' ious degrees of deflation of the tires, and means for actuating said indicating means comprising a plurality of circuits supplied with current from said storage battery, and means controlled by I tilting of the axles due to tire deflation for varying the flow of current through the circuits. 3. The-combination with an automobile hav axles and wheels-on the axles with pneucating the various degrees-of deflation of the tires, and means for actuating said indicating on the automobile so that it may be viewed from means including electric circuits with variable walk mum. a ncav auu. slaving sum LUI muwutmg the various degrees of deflation of the tires, and means for actuating said indicating means including electric circuits with variable resistances therein, and devices mounted adjacent to the central portions of the axles and operative in response to tilting of said axles due to tire deflation to vary the resistances.

- 5. The combination with an automobile provided with a storage battery and having axles and wheels on the axles with pneumatic tires thereon, of a tire indicator mounted on the automobile so that it may be viewed from the driver's seat and having means for indicating the various degrees of deflation of each tire, and means for actuating said indicating means comprising circuits corresponding in number to the wheels and supplied with current from said storage battery, variable resistances in the circuits, and de- 80 vices mounted on the central portions of the axles and operative in response to tilting of said axles due to tire deflation to vary the resistances.

6. The combination with a vehicle having wheels with pneumatic tires thereon, of an indicator for registering the amount of pressure in the tires, mounted on the vehicle and comprising pointers and graduated scales, and means for actuating the indicator, controlled by tilting due to tire deflation and automatically operative progressively to move the pointers with respect to,

the scales as the angle of tilt increases.

7. The combination with an automobile having axles and wheels on the axles with pneumatic tires thereon, of an indicator for registering the amount of pressure in the tires, mounted on the automobile so that it may be viewed from the drivers seat and comprising pointers and graduated scales, and means for actuating the indicator, controlled by tilting of the axles due to tire deflation and automatically operative progressively to move the pointers with respect to the scales in response to progressive tilting of said axles.

8. The combination with an automobile having axles and wheels on the axles with pneumatic tires thereon, of an indicator for registering the amount of pressure in the tires mounted on the automobile and comprising movable pointers and raduated scales, and automatic means for progressively moving the pointers with respect to the scales in response to progressive deflation of the tires, including electric circuits and means controlled by tilting of the axles due to tire deflation for varying the flow of current through the circuits.

- 9. The combination with an automobile provided with a storage battery and having axles and wheels on the axles with pneumatic tires thereon, of an indicator for registering the amount of pressure in the tires, mounted on the automobile. so that it may be viewed from the driver's seat and comprising pointers and graduated scales, and automatic means for progressively moving the pointers with respect'to the scales in response to progressive deflation of the tires, embodying a plurality of electric circuits supplied with current from the storage battery, variable resistances in said circuits, and devices mounted on the central portions of the axles for varying the resistances in response to tilting of the axles due to tire deflation.

10. The combination with an automobile having a front and a rear axle and wheels with pneumatic tires at the ends of the axles, of a tire indicator mounted on the automobile so that it-may 0e viewed rrom the driver's seat 8116 comprising a graduated scale and a coacting pointer adapted when moved in one direction relatively to the scale to indicate the various degrees of deflation of the front tire at one side of the automobile, and adapted when moved in the other direction relatively to the scale to indicate the various derees of deflation of the rear tire at said one side of the automobile; means for progressively moving the pointer in said one direction in response to progressive deflation of said front tire, comprising an electric circuit with a variable resistance therein, and a device controlled by tilting of the front axle relatively to the rear axle as the result of deflation of said front tire for varying the resistance; and means for progressively moving the pointer in said other direction in response to progressive deflation of said rear tire, comprising an electric circuit with a variable resistance therein, and a device controlled by tilting of the rear axle relatively to the front axle due to deflation of said rear tire for varying the last mentioned resistance.

11. The combination with an automobile having a front and a rear axle and wheels with pneumatic tires at the ends of the axles, of a tire indicator mounted on the automobile so that it may be viewed from the driver's seat and comprising a graduated scale and a. coacting pointer adapted when movedin one direction relatively to the scale to indicate the various degrees of deflation of the front tire at one side of the automobile, and adapted when moved in the other direction relatively to the scale to indicate the various degrees of deflation of the rear tire at said one side of the automobile; means forprogressively moving the pointer in said one direction in response to progressive deflation .of said front tire, comprising an electric circuit with a variable resistance therein and an automatic resitance varying device mounted on the central portion of the front axle and controlled by tiltingof the front axle relatively to the rear axle as the result of deflation of said front tire; and means for progressively moving the pointer in said otherwdirection in response to progressive deflation of said rear tire, comprising an electric circuit with a variable resistance therein, and a device for automatically varying the last mentioned resitance, mounted 7 on the: central portion of the rear axle controlled by tilting of said rear axle relatively to the front axle as the result of deflation of said rear tire.

12.- The combination with a vehicle having wheels with pneumatic tires thereon, of a tire indicator mounted on the vehicle and comprising movable members for indicating deflation of the tires and thermo-responsive elements adapted when heated to move said indicating members, and means for automatically heating the thermo- DOnsive elements upon deflation of the tires.

13. The combination with a vehicle having wheels with pneumatic tires thereon, of a tire prising means for automatically heating the first mentioned thermo-responsive element-upon de- Q progre ve deflation of said rear s,1ss,ses I l v cator whereby themembers are automatically flation of said one tire, and means for automatically heating said second thermo-reebonsive elemeat upon deflation of said another tire.

14. In combination with an automobile having a front and a rear axle and wheels at ends of the axles with pneumatic tires thereon, of a tire indicator mounted on the vehicle and comprising a movable member adapted when moved in one direction to indicate deflation of the front tire at one side of the automobile and adapted when moved in the other direction to indicate deflation of the rear tire at said one side of the automobile, a thermo-responsive element connected to said member and adapted when heatedto move the member in said one direction, and a second thermo-responsive element connected to the member and adapted when heated to move the member in said other direction; and an actuator for the indicator comprising means controlled by tilting of the front axle due to deflection of said front tire for automatically heating the flrst mentioned thermo-responsive element, and means controlled by tilting of the rear axledue to deflation of said rear tire for automatically heating said second thermo-responsive element.

15. The combinationwith an automobile having a front and a rear axle, and wheels with pneumatic tires, at the ends of the axles, of a tire indicator mounted on the automobile so that it may be viewed from the driver's seat and comprising a graduated scale, a coacting' pointer adapted when moved in one direction relatively to the scale to indicate the various degrees of deflation of the front tire at one side of the automobile and adapted when moved in, the other direction relatively to the scale to indicate the various degrees of deflation of the rear tire at said one side of the automobile, an element connected to the pointer and adapted when current is passed therethrough to distend and move the pointer in said one direction and a second element connected to the pointer in opposed relation the flrst mentioned element and distend and move the pointer in said other direction; means for controlling the indicator so that the pointer is moved progressively in said one direction in response to progressive deflation of said front tire, cqnprising an electric circuit for said flrst mentioned element, a resistancein said circuit, and a control device operative in response to initial tilt of the 'front'axle'due to deflation of said front tire to close said circuit and further operative progressively to decrease inganelectriccircuitfor-saia resistance insaidlastmentionedeircuitands ,oftherearaxleduetodefl'ationofsaid-reartire to close said last mentioned circuit and fm'ther operativeto'decreasetheresistance inthelattercirouitas'tilting ofsaidrearaxle increasesduetoprogrelllvedeflationofsaidresr with pneumatic dicating the various insthe .mcsns'and having a in responseto progressive tilting .the opposite direction due to deflation of said moved upon deflation of the tires.

'17. the combination witha vehicle front and rear axle and wheels on the axles with pneumatic tires mounted on the vehicle so that it is visible from the driver's seat and provided with means for indicating the various degrees of deflation of each tire, and means for automatically actuating said indicating means including an electric circuitior each means with a therein, and a pair of control devices associated with the axles respectively and arranged and constructed so that they progressive tilting of the axles in one direction due to deflation of the tires at. oneside of the vehicle to vary progressively the resistances in certain of the circuits and in rmponse to progressive tilting of the axles in'the other direction due to deflation of the tires at the other side of the vehicle to vary progressively the resistances in the other circuits.

18. The combination with thereon, of a tire indicator.

having a:

variable resistance operate in response to a vehicle having a cross axle and wheels on the ends of the axle with pneumatic tires thereon, of a tire indicator mounted on the vehicle'so that it is visible from the driver's seat and provided with means for indicatlng the various degrees of deflation of one of the tires and also provided with means for indicating the various degrees of deflation of the other tire, and means for automatically actuating the indicator comprising an electric circuit with a variable resistance therein for the flrst mentioned indicating means, an electrical circuit 'with a-variable'resistance therein for the second mentioned indicating means, and a control device associated with the axle and arranged so that in response to progressive tilting of the axle in one gressively varies the resistance in said flrst-mentioned' circuit and also arrangeds'o that in re- .direction due to deflation of said one tire it prosponse to progressive tilting of the axle in the opposite direction due to deflation of said other tire it progressively varies, the resistance in the second mentioned control circuit. l 19. 1'he combination with a vehicle having'a cross axleandwheelsontheendsoitheaxle tires thereon, of a tire indicator mounted on the adapted to control the flrst mentioned indicatingmeans andhsving avariable resistance therein and means for-automatically schist-- indicator comprising an electrical circuit vehicle so that it is visible from the driver's seat and provided with means for 'indegrees of deflation'of one-- mounted on theaxle, an electrical circuit adapt i edto 'control the second 'mentioned indicating edontheaxlebetween the two and soasto move lengthwise of the axle'and arranged -so' that in response to progressiveitilting-of the sale tire "it progressively flrst mentioned circuit in one direction due to deflation of said one and also arranged so that other time it progressively variu-the in the second mentioned circuit.

variable resistance mounted also on'the axle, and an element mount- I varies the resi'stanceinfthe of the axle in mc mwdnm 

